I think it's a great idea for your wife to start using the Alpha techniques in the bonus Alpha Book to teach your dog that she is higher than him in the pecking order. In fact, it's essential if she wants the proper respect from him. It might be that you still remain the Top Dog, but she comes in at a close second. That's the way it is in my family. My husband is Alpha, then me, then our 15 month old dog, and then the 9 month old pup.
The thing that concerns me in your post is that you mentioned the dog growls at your wife when he is chewing on a hoof. That kind of behavior is not appropriate and should be sorted out ASAP. Does your dog only growl when he has a hoof, or with all foods or treats? If it's with all foods, you should have a look at the Food Bowl Aggression info in the "Quick Guide to Aggression" ebook for tips on how to fix it. If it just occurs with the hooves, then you may want to change the tips a little so that they can apply to your particular situation. Or you could try removing the hooves altogether.
Hopefully your wife's use of the Alpha techniques will help with this aggression issue also. It's very important for the dog to know that it is actually at the bottom of the pack!
Good luck
